Abstract: A bulk acoustic wave (BAW) resonator includes: a plurality of acoustic reflectors disposed in a substrate; a lower electrode disposed over the plurality of acoustic reflectors; a piezoelectric layer disposed over the lower electrode; and a plurality of upper electrodes, disposed over the piezoelectric layer. One of the plurality of upper electrodes is formed over a respective one of the plurality of acoustic reflectors. Each of the plurality of upper electrodes, the piezoelectric layer, the lower electrode, and each of the acoustic reflectors form an individual active area.

Abstract: A bulk acoustic wave (BAW) resonator includes: a plurality of acoustic reflectors disposed in a substrate; a lower electrode disposed over the plurality of acoustic reflectors; a piezoelectric layer disposed over the lower electrode; and a plurality of upper electrodes, disposed over the piezoelectric layer. One of the plurality of upper electrodes is formed over a respective one of the plurality of acoustic reflectors. Each of the plurality of upper electrodes, the piezoelectric layer, the lower electrode, and each of the acoustic reflectors form an individual active area.

Abstract: An acoustic resonator device includes a temperature compensation structure disposed beneath the first electrode and above the substrate.

Abstract: Film bulk acoustic resonators (FBARs) having frame elements and filters including the resonators are described.

Abstract: A signal processing device includes a first acoustic resonator, a second acoustic resonator disposed on the first acoustic resonator, and a coupling layer between the first and the second acoustic resonators. The first acoustic resonator has a first electrical impedance and a first resonance frequency and includes a first set of electrodes, and a first piezoelectric layer having a first thickness, disposed between the first set of electrodes. The second acoustic resonator has a second electrical impedance and a second resonance frequency, and includes a second set of electrodes, and a second piezoelectric layer having a second thickness, wherein the second piezoelectric layer is disposed between the second set of electrodes. The first electrical impedance at a passband frequency of the device substantially differs from the second electrical impedance at the passband frequency of the device. The first and second resonance frequencies are substantially different from each other.

Abstract: In accordance with a representative embodiment, a BAW resonator structure, comprises a first BAW resonator, comprising: a first lower electrode having a first electrical resistance; a first upper electrode having a second electrical resistance; and a first piezoelectric layer disposed between the first lower electrode and the first upper electrode. The BAW resonator structure also comprises a second BAW resonator, comprising: a second lower electrode having the second electrical resistance; a second upper electrode having the first electrical resistance; and a second piezoelectric layer disposed between the second lower electrode and the second upper electrode. The BAW resonator structure also comprises an acoustic coupling layer disposed between the first BAW resonator and the second BAW resonator. The first electrical resistance is less than the second electrical resistance. An communication device comprising a coupled resonator filter (CRF) is also disclosed.

Abstract: In accordance with a representative embodiment, a BAW resonator structure, comprises a first BAW resonator, comprising: a first lower electrode having a first electrical resistance; a first upper electrode having a second electrical resistance; and a first piezoelectric layer disposed between the first lower electrode and the first upper electrode. The BAW resonator structure also comprises a second BAW resonator, comprising: a second lower electrode having the second electrical resistance; a second upper electrode having the first electrical resistance; and a second piezoelectric layer disposed between the second lower electrode and the second upper electrode. The BAW resonator structure also comprises an acoustic coupling layer disposed between the first BAW resonator and the second BAW resonator. The first electrical resistance is less than the second electrical resistance. An communication device comprising a coupled resonator filter (CRF) is also disclosed.

Abstract: A signal processing device includes a first acoustic resonator, a second acoustic resonator disposed on the first acoustic resonator, and a coupling layer between the first and the second acoustic resonators. The first acoustic resonator has a first electrical impedance and a first resonance frequency and includes a first set of electrodes, and a first piezoelectric layer having a first thickness, disposed between the first set of electrodes. The second acoustic resonator has a second electrical impedance and a second resonance frequency, and includes a second set of electrodes, and a second piezoelectric layer having a second thickness, wherein the second piezoelectric layer is disposed between the second set of electrodes. The first electrical impedance at a passband frequency of the device substantially differs from the second electrical impedance at the passband frequency of the device. The first and second resonance frequencies are substantially different from each other.

Abstract: An electrical impedance transformer comprises a first film bulk acoustic resonator (FBAR), having a first electrical impedance and a first resonance frequency. The electrical impedance transformer also comprises: a second FBAR, having a second electrical impedance and a second resonance frequency, and being disposed over the first FBAR. The electrical impedance transformer also includes a decoupling layer disposed between the first and the second FBARs. The first electrical impedance differs from the second electrical impedance and the first and second resonance frequencies are substantially the same.

Abstract: A coupled acoustic resonator adapted for single-ended input to differential output signal transformation, comprises a single stack. The single stack comprises: a first film bulk acoustic resonator (FBAR) comprising a single-ended input; a second FBAR disposed over the first FBAR comprising a first differential output and a second differential output; an acoustic decoupling layer disposed between the first FBAR and the second FBAR; and a resonant element comprising a resonant inductor and a parasitic capacitor connected in parallel. The resonant element is connected to the first differential output and is operative to substantially balance a signal from the first differential output with a signal from the second differential output. The first differential output is connected to an external circuit comprising a parasitic impedance, and the resonant inductor has an inductance selected to substantially maintain the balance.

Abstract: An electrical impedance transformer comprises a first film bulk acoustic resonator (FBAR), having a first electrical impedance and a first resonance frequency. The electrical impedance transformer also comprises: a second FBAR, having a second electrical impedance and a second resonance frequency, and being disposed over the first FBAR. The electrical impedance transformer also includes a decoupling layer disposed between the first and the second FBARs. The first electrical impedance differs from the second electrical impedance and the first and second resonance frequencies are substantially the same.

Abstract: A bulk acoustic wave device includes an acoustic decoupler between first and second film bulk acoustic resonators (FBARs). The first FBAR is resonant at a resonant frequency of the device and includes first and second planar electrodes abutting opposite sides of a first resonator volume free of any intervening electrodes and containing piezoelectric material disposed for acoustic vibrations parallel to a propagation axis normal to the first and second electrodes. The first FBAR has a first electrical impedance parallel to the propagation axis. The second FBAR is resonant at the resonant frequency and includes third and fourth planar electrodes abutting opposite sides of a second resonator volume free of any intervening electrodes and containing piezoelectric material disposed for acoustic vibrations parallel to the propagation axis. The second FBAR has a second electrical impedance parallel to the propagation axis and different from the first electrical impedance.

Abstract: In a filter having a half-ladder structure comprising an alternating series of series branches and shunt branches, including a signal input and a signal output related to a common ground, at least one series branch or one parallel branch of the filter is configured as a BAW device comprising a first BAW resonator and a second BAW resonator connected either antiparallel or antiseries. The second harmonic emission generated by the first BAW resonator substantially cancels the second harmonic emission of the second BAW resonator and the second harmonic emission of at least one other series branch or one other parallel branch of the filter. By this method, the filter's second harmonic emissions are reduced.

Abstract: An acoustic resonator and a communication device with an acoustic resonator are described.

Abstract: A hybrid acoustic resonator filter and a communication device with a hybrid acoustic resonator filter is described.

Abstract: A bandpass filter includes input and output terminals, first and second acoustic resonators, and an acoustic coupling layer. The first acoustic resonator includes first and second electrodes, and a piezoelectric layer between the first and second electrodes. The first electrode of the first acoustic resonator is connected to the input terminal. The second acoustic resonator includes first and second electrodes, and a piezoelectric layer between the first and second electrodes. The acoustic coupling is provided between the second electrode of the first acoustic resonator and the first electrode of the second acoustic resonator. The output terminal is connected to the second electrode of the second acoustic resonator. A capacitor extends between the input terminal and the output terminal. The filter's frequency response includes at least two transmission zeros.

Abstract: A method and circuit matches a device to n filters, wherein each filter is a SAW filter, BAW filter, or FBAR filter. The method and system: (a) provide an inductor or transmission line connected between a common terminal and ground; (b) provide a plurality of capacitance values (C1m, C2m, . . . , Cnm) each corresponding to one of the n filters; and (c) for each of the n filters, directly connect a first terminal of the filter to either: (1) the common terminal, or (2) a first terminal of a corresponding capacitor having the correspondence capacitance value calculated in step (b), where a second terminal of the corresponding capacitor is directly connected to the common terminal.

Abstract: In a filter having a half-ladder structure comprising an alternating series of series branches and shunt branches, including a signal input and a signal output related to a common ground. at least one series branch or one parallel branch of the filter is configured as a BAW device comprising a first BAW resonator and a second BAW resonator connected either antiparallel or antiseries. The second harmonic emission generated by the first BAW resonator substantially cancels the second harmonic emission of the second BAW resonator and the second harmonic emission of at least one other series branch or one other parallel branch of the filter. By this method, the filter's second harmonic emissions are reduced.

Abstract: A film acoustically-coupled transformer (FACT) has a first and a second stacked bulk acoustic resonator (SBAR 1, SBAR 2). Each SBAR has a stacked pair of film bulk acoustic resonators (FBARs) and an acoustic decoupler between the FBARs. Each FBAR has opposed planar electrodes and a layer of piezoelectric material between the electrodes. A first electrical circuit connecting one of the FBARs of SBAR1 to one of the FBARs of SBAR 2 and a second electrical circuit connecting the other of the FBARs of SBAR 1 to the other of the FBARs of SBAR 2. The first electrical circuit connects the respective FBARs in parallel and second electrical circuit connects the respective FBARs in series. A shunt inductor is included from the reception path to ground.

Abstract: A method and circuit matches a device to n filters, wherein each filter is a SAW filter, BAW filter, or FBAR filter. The method and system: (a) provide an inductor or transmission line connected between a common terminal and ground; (b) provide a plurality of capacitance values (C1m, C2m, . . . , Cnm) each corresponding to one of the n filters; and (c) for each of the n filters, directly connect a first terminal of the filter to either: (1) the common terminal, or (2) a first terminal of a corresponding capacitor having the correspondence capacitance value calculated in step (b), where a second terminal of the corresponding capacitor is directly connected to the common terminal.